unplot

Draw a function. Get the math.

Desmos plots a formula you type. unplot does the reverse: you draw a smooth curve y = f(x) on a Cartesian plane, and it hands back the exact function — as clean LaTeX you can differentiate, integrate, edit, and save.

What you get back is exactly what you drew: a shape-preserving spline that is a valid function by construction, not a guess. And when your drawing really is a simple function, unplot also proposes a compact closed form — f(x) ≈ 3x², cos x, 1/x — always shown with its error, never presented as exact.

Features

• Draw a function, get exact LaTeX. The stroke becomes a shape-preserving PCHIP spline that is a valid function by construction — the pen hard-blocks anything that isn't one (no reversing in x, no vertical spikes).
• Edit everything. Drag knots and tangent handles, translate the whole curve, undo/redo — or type x, y points directly and plot them.
• Calculus, exactly. Differentiate and integrate the curve. When it's a recognized function the result is exact and symbolic — d/dx of a drawn x³ is 3x², not a lumpy numeric approximation.
• A "prettier function." An error-gated closed-form guess — polynomials, waves of any frequency, and pole-shaped rationals — shown beside the exact output with its max/RMS error, never in place of it.
• Copy anywhere. Export the function as LaTeX, Desmos, or Wolfram.
• Save & reopen. A versioned, cross-platform .unplot document stores just the points, so a saved curve reopens fully editable.
• Cross-platform, offline, light/dark. Windows, macOS, and Linux. No network access, ever.

Install

Download the installer for your platform from the latest release:

• Windows — .msi or .exe
• macOS — .dmg (universal: Apple Silicon + Intel)
• Linux — .deb (Debian/Ubuntu), .rpm (Fedora), or .AppImage (any distro). On rolling-release distros the .deb/.rpm are the most robust because they use your system's WebKitGTK — see docs/linux-packaging.md if an AppImage won't start.

The builds aren't code-signed yet, so your OS will warn about an unidentified developer the first time you open the app. To get past it:

• macOS — right-click the app and choose Open, then Open again (only needed once). If it still refuses, clear the quarantine flag: xattr -dr com.apple.quarantine /Applications/unplot.app.
• Windows — on the SmartScreen prompt, click More info → Run anyway.

Run from source

Needs Rust, Node 22+, pnpm, and just. On Linux you also need the Tauri prerequisites (WebKitGTK etc.).

pnpm install     # frontend dependencies
just dev         # run the desktop app (Vite + Tauri)
just test        # full test suite: Rust core + frontend

How it works

A headless Rust core (crates/curve-engine/) does the math — spline fitting, analytic calculus, the closed-form approximator, the symbolic layer, and file I/O — and never imports the UI, so it is fully unit-tested on its own. A Canvas 2D + TypeScript frontend (src/) handles drawing, editing, and the KaTeX math panel. Tauri (src-tauri/) glues them into a desktop app. The design decisions and roadmap live in docs/PLAN.md.

Contributing

Contributions are welcome — see CONTRIBUTING.md for setup, the architecture, and the conventions, and please follow the Code of Conduct. Report bugs or request features through the issue tracker; for security problems, see SECURITY.md.

License

MIT © Vitor Wilson